What to plant this week in Ann Arbor, MI
Ann Arbor gardeners are officially in the 'wait and watch' phase as the ground remains too cold for sowing, with an average last frost date still lingering until April 21. While you cannot plant outdoors yet, this is the perfect time to start those cool-season giants like parsnips, leeks, and garlic indoors or under protection. Keep your eyes on the calendar; once that frost threat passes, you'll be ready to transplant a massive list of summer crops including zucchini, corn, and okra.
The next 7 days
Ann Arbor, MIGrowing in Ann Arbor right now
- Soil in Ann Arbor's clay-heavy glacial till is still freezing or waterlogged; avoid working it until temperatures consistently rise above 40°F to prevent compaction. Focus your energy indoors now by starting seeds for the upcoming crop surge of bush beans, squash, and tomatoes that will hit prime growth once frost ends.
- Take advantage of our urban microclimates in neighborhoods like Old West or near the Huron River; these warmer pockets might allow you to start transplanting heat-loving crops like basil or nasturtium a few weeks early if you can protect them from late spring chills.
- Our region's typical wet springs mean drainage is critical; ensure your new beds and raised planters have excellent airflow to prevent root rot once the thaw accelerates in late April.
Sow this week
No direct sowing windows open this week.
Transplant this week
Nothing is due to go out this week.
Harvest soon
45 crops- Basil
- Borage
- Bush Bean
- Cantaloupe
- Celery
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Dahlia
- Edamame
- Fennel
- Flour Corn
- French Marigold
- Garden Verbena
- Garlic
- Ghost Pepper (Bhut Jolokia)
- Gourd (Ornamental/Bottle)
- Honeydew Melon
- Leek
- Lima Bean
- Lisianthus (Prairie Gentian)
- Loofah (Luffa)
- Malabar Spinach
- Nasturtium
- Okra
- Ornamental Sweet Potato Vine
- Parsnip
- Pole Bean
- Potato
- Pumpkin
- Roselle (Cranberry Hibiscus)
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Sweet Corn
- Sweet Potato
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Succession sow bush beans and sweet corn every two weeks for continuous harvests through summer.
- Pinch back the tips of basil and okra to encourage bushier growth rather than flowering too early.
- Add a thin layer of straw or shredded leaves around heavy feeders like pumpkins and squash to retain moisture.
Pest & disease watch
- Watch for overwintering aphids and mites sheltering on dormant shrubs like forsythia or boxwood, ready to explode as temperatures rise above freezing.
- Early spring fungal issues like powdery mildew can strike quickly if our characteristic humid springs coincide with cool nights; keep good air circulation in your nursery rows.
- Watch for early-season caterpillars appearing on young seedlings once the first warm rain hits the soil.
Watering this week
Provide about 1 to 2 inches of water per week, applying it deeply in the morning to reduce evaporation and disease risk.
Harvest zucchini and summer squash early in the day when they are most tender and flavorful for your table.
Ann Arbor gardening questions
3Can I plant my garlic now, or is it too late?
Yes, this is actually prime time to plant hardy garlic varieties in Ann Arbor; get them into the cool ground before the heavy rains of May set in for best bulb formation. Ensure you choose a well-drained spot, as our clay soils can be tricky if water sits around the bulbs.
My zucchini and corn seeds are ready, when exactly should I put them outside?
Wait until after April 21st when the risk of frost passes, then transplant your warm-weather crops like zucchini and sweet corn once the soil has warmed up significantly. Aim for a week or two after the last frost date to ensure the young plants don't suffer from any sudden cold snaps.
What should I do with my tomato starts that are already huge?
Keep your indoor tomato seedlings under bright grow lights and at temperatures between 65-70°F until they are ready for the open field in mid-to-late May. Do not rush them outside yet, as our late April frosts can easily kill tender tomato foliage.
Other cities in zone 6a
12See the full zone 6a guide → · Plan your Ann Arbor garden in SproutGuide →